Less than half of UK prescriptions for antipsychotic drugs are being issued to treat the serious mental illnesses for which they are mainly licensed, according to researchers.
Instead, they may often be prescribed “off label” to older people with other conditions, such as anxiety and dementia, despite the greater risk of potentially serious side effects in this age group.
Researchers, from University College London, analysed GP prescribing patterns for first and second generation antipsychotic drugs across the UK from 2007-11, covering nearly 48,000 patients.
“Our findings suggest that further effort is required to decrease primary care antipsychotic prescriptions in dementia”
The study focused on the three most commonly prescribed first generation antipsychotics – haloperidol, chlorpromazine and trifluoperazine – and three most popular second generation drugs – olanzapine, quetiapine and risperidone.
The researchers looked at the average daily dose, as well as the duration of the treatment.
Almost 14,000 were prescribed first generation antipsychotics, almost 28,000 second generation drugs and almost 6,000 both.
The prescribing rate was significantly higher in women than in men, and people aged 80 and above were more than twice as likely to be treated with an antipsychotic as those aged 40-49.
However, of those receiving first generation antipsychotics, less than 50% had a diagnosis of psychosis or bipolar disorder.
Meanwhile, for second generation drugs, the numbers prescribed the drugs with a serious condition ranged from 36% for quetiapine to 62% for olanzapine.
Common diagnoses among patients receiving the drugs for less serious conditions included anxiety, depression, dementia, sleep and personality disorders, said the study authors.
For example, risperidone was prescribed for anxiety in 14% of cases, depression without psychoses in 22%, dementia in 12%, sleep disorders in 11% and personality disorder in 4% of cases.
When prescribed for less serious conditions, doses tended to be lower and of shorter duration – except for hyperactivity and dementia.
The researchers highlighted that second generation antipsychotics were not recommended for dementia, because of the increased risk of stroke and death associated with them in older people.
“Reducing the potential harm associated with antipsychotics in dementia has been emphasised as a priority by organisations such as the Department of Health,” they stated in the online journal BMJ Open.
They added: “Our findings suggest that further effort is required to decrease primary care antipsychotic prescriptions in dementia, and that assessing time trends in antipsychotic prescribing in this group is an important area for future research.”